diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 *Megaparsec follows [SemVer](https://semver.org/).*
 
+## Megaparsec 9.8.3
+
+* Added `INLINE` pragmas to the built-in `Stream` instances for `Text` and
+  `ByteString`, restoring the performance they had before 9.3.0. [Issue
+  612](https://github.com/mrkkrp/megaparsec/issues/612).
+
 ## Megaparsec 9.8.2
 
 * Fixed tab expansion in the rendering of the offending line so that it
diff --git a/Text/Megaparsec/Stream.hs b/Text/Megaparsec/Stream.hs
--- a/Text/Megaparsec/Stream.hs
+++ b/Text/Megaparsec/Stream.hs
@@ -201,6 +201,14 @@
     | B.null s = Nothing
     | otherwise = Just . second ShareInput $ B.splitAt n s
   takeWhile_ p (ShareInput s) = second ShareInput $ B.span p s
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 instance Stream (ShareInput BL.ByteString) where
   type Token (ShareInput BL.ByteString) = Word8
@@ -216,6 +224,14 @@
     | BL.null s = Nothing
     | otherwise = Just . second ShareInput $ BL.splitAt (fromIntegral n) s
   takeWhile_ p (ShareInput s) = second ShareInput $ BL.span p s
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 instance Stream (ShareInput T.Text) where
   type Token (ShareInput T.Text) = Char
@@ -231,6 +247,14 @@
     | T.null s = Nothing
     | otherwise = Just . second ShareInput $ T.splitAt n s
   takeWhile_ p (ShareInput s) = second ShareInput $ T.span p s
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 instance Stream (ShareInput TL.Text) where
   type Token (ShareInput TL.Text) = Char
@@ -246,6 +270,14 @@
     | TL.null s = Nothing
     | otherwise = Just . second ShareInput $ TL.splitAt (fromIntegral n) s
   takeWhile_ p (ShareInput s) = second ShareInput $ TL.span p s
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 -- | This wrapper selects the no-input-sharing 'Stream' implementation for
 -- 'T.Text' ('TL.Text') and 'B.ByteString' ('BL.ByteString'). This means
@@ -371,6 +403,14 @@
   take1_ s = second unShareInput <$> take1_ (ShareInput s)
   takeN_ n s = second unShareInput <$> takeN_ n (ShareInput s)
   takeWhile_ p s = second unShareInput $ takeWhile_ p (ShareInput s)
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 instance Stream BL.ByteString where
   type Token BL.ByteString = Token (ShareInput BL.ByteString)
@@ -383,6 +423,14 @@
   take1_ s = second unShareInput <$> take1_ (ShareInput s)
   takeN_ n s = second unShareInput <$> takeN_ n (ShareInput s)
   takeWhile_ p s = second unShareInput $ takeWhile_ p (ShareInput s)
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 instance Stream T.Text where
   type Token T.Text = Token (ShareInput T.Text)
@@ -395,6 +443,14 @@
   take1_ s = second unShareInput <$> take1_ (ShareInput s)
   takeN_ n s = second unShareInput <$> takeN_ n (ShareInput s)
   takeWhile_ p s = second unShareInput $ takeWhile_ p (ShareInput s)
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 instance Stream TL.Text where
   type Token TL.Text = Token (ShareInput TL.Text)
@@ -407,6 +463,14 @@
   take1_ s = second unShareInput <$> take1_ (ShareInput s)
   takeN_ n s = second unShareInput <$> takeN_ n (ShareInput s)
   takeWhile_ p s = second unShareInput $ takeWhile_ p (ShareInput s)
+  {-# INLINE tokenToChunk #-}
+  {-# INLINE tokensToChunk #-}
+  {-# INLINE chunkToTokens #-}
+  {-# INLINE chunkLength #-}
+  {-# INLINE chunkEmpty #-}
+  {-# INLINE take1_ #-}
+  {-# INLINE takeN_ #-}
+  {-# INLINE takeWhile_ #-}
 
 -- | Type class for inputs that can also be used for debugging.
 --
@@ -603,9 +667,9 @@
           pstateLinePrefix =
             if sameLine
               then -- NOTE We don't use difference lists here because it's
-              -- desirable for 'PosState' to be an instance of 'Eq' and
-              -- 'Show'. So we just do appending here. Fortunately several
-              -- parse errors on the same line should be relatively rare.
+                -- desirable for 'PosState' to be an instance of 'Eq' and
+                -- 'Show'. So we just do appending here. Fortunately several
+                -- parse errors on the same line should be relatively rare.
                 pstateLinePrefix ++ f ""
               else f ""
         }
diff --git a/megaparsec.cabal b/megaparsec.cabal
--- a/megaparsec.cabal
+++ b/megaparsec.cabal
@@ -1,6 +1,6 @@
 cabal-version:   2.4
 name:            megaparsec
-version:         9.8.2
+version:         9.8.3
 license:         BSD-2-Clause
 license-file:    LICENSE.md
 maintainer:      Mark Karpov <markkarpov92@gmail.com>